The proposed study is to develop a behavioral scale to assess postoperative pain in young children for both clinical and research applications. Currently, the lack of standardization of postoperative pain management in children results in the undermedication of many children. The most formidable obstacle for systematically evaluating methods of controlling postoperative pain in children is the lack of an objective method of pain assessment. Without such an assessment instrument, accurate matching of analgesic use to the child's postoperative pain level is impossible. While significant efforts have been made recently to assess pain in infants, school age and adolescent children, very few studies address pain in children between 1 an 5 years to be studied in this proposal. Approximately 100 children between the ages of 12 and 60 months, scheduled for hernia or hydrocele surgeries will be the subjects of the study. Parents will be interviewed at the child's presurgical physical to gather demographic, psychosocial and medical information relevant to the child's surgery. children will be observed pre and postoperatively with the proposed Pain Assessment Scale (PAS). Children and parents will also be observed for their interactions pre and postoperatively and these findings will be related to the child's pain score. Intra and postoperative vital signs, and anesthetic, analgesic and surgical protocols will be recorded and related to the child's PAS score. The child will also be evaluated for postoperative pain with visual analog scale ratings made by a parent and a nurse at specified intervals. Two observers will be present for 20% of the cases to assess interrater reliability with the pain scale. The psychometric properties of the pain scale will be assessed. The development and testing of the proposed observational scale of pain in young children is the first step toward the establishment of a reliable and valid instrument for assessing pain related to surgical procedures in this population. The instrument is to be designed for ease of clinical administration by recovery room staff for assessing the effectiveness of strategies of postoperative pain management. Such an objective method for evaluating the efficacy of surgical, pharmacological and behavioral management of postoperative pain should ultimately make the safe yet effective management of pain possible in these children.